Operation Manual
FarSounder, Inc.
F31552 (Rev. 3.8.0)
Page 42 of 69
Figure 41. Alarm configuration settings
The FOV setting specifies the sector width of the alarm trigger volume in degrees. For example 60.0° means
that only targets within 30.0° to either side of the bow will trigger the alarm. The Max Range setting specifies
the maximum range extent of the alarm trigger volume. The Min Range setting specifies the minimum range
extent of the alarm trigger volume. The Max Depth setting specifies the maximum depth of the alarm trigger
volume. The Max Range, Min Range, and Max Depth settings are displayed using the unit of measure
defined in the Configuration Manager's System Settings.
Like any marine sensor (radar, echo sounder, etc), the FarSounder sonar systems may detect spurious
noises. These "noises" include reflections from bubbles in the water column and small bits of debris in the
water. The alarm hit number specifies the number of pings in a row that a target must be detected within
the alarm volume to trigger the alarm. By specifying a number higher than 1 for the hit number, false alarms
can be reduced. For every ping with a detection within the alarm volume an internal counter is incremented.
For every ping without a detection within the volume the internal counter is decremented until reaching a
minimum value of 0. If the counter value reaches the hit number specified by the user, the alarm is triggered.
5.5. Additional Configuration Manager Options
In addition to the alarm settings, the 3D Sonar Display includes other Configuration Manager options.
Minimum Depth Display
When the Show Minimum Depth checkbox is set, the shallowest depth detected by the sonar ahead of the
vessel within a designated route safety zone is displayed as a single number at the top left of the 3D Sonar
